Literally everyone agrees that more housing should be built and it shouldn’t be too hard to do so (just don’t sacrifice safety standards). However, simply building more housing isn’t enough. A lot of the housing built nowadays are built for the rich while there aren’t many small starter-homes being built. We need to do so much more than just building more homes, or else we risk the rich just buying them all up again.
It means he’s an idiot who wants to convince other idiots that this will mean less taxes for them, while it just means that poor people will be taking up the tax burden while the rich get away without paying anything.